There are many viruses which may cause respiratory infections in the normal and immunocompromised host. This study looks at the cystic fibrosis patient to determine the incidence of respiratory viral disease in the group, and, more specifically examining CF patients undergoing or about to undergo gene therapy, are there viruses present which might interfere with using a replication-deficient adenovirus vector as the gene therapy modality. Bronchial lavages and brushings and nasal brushings will be collected and cultured by the vial assay for the detections of herpes simplex virus, cytomegalovirus, varicella-zoster virus, respiratory syncytial virus, influenza virus, parainfluenza virus, and adenovirus.